Design And Accomplishment Of Micro-LIBS3D Precision Scanning System

Laser Induced Breakdown Spectroscopy (LIBS) is a qualitative and quantitativediagnostics with advantages of minor damage, real time, standing off, in-situ,multi-elements detection and no sample preparation etc. It has been successfullyapplied to many areas with different degrees of success. Shellfish is known as naturalbio-marker, the composition and content of shell can indicate the change of climatein the area. LIBS technology can analyze in the form of solid, liquid and gas samples,and do not need sample pretreatment or does just simple sample pretreatment. Thedestructive of the sample is very small, and sample is measured rapidly, just likereal-time measurement. However, the shell growth layer’s thickness is just microndimension quarterly or monthly, the content of the corresponding component elementsis shown in the spatial distribution of micron-sized, traditional LIBS is not unable toanalyze the element composition of the object. Micro-LIBS derives from LIBS,because the energy of the laser is little, the spot of laser ablation is small, whichimproves the spatial resolution of sample analysis, it is enough to analyze thecomposition of shell.Micro-LIBS is a spectroscopy analysis technology with micro-Joule to excite thesurface of the object, it needs three-dimensional lattice scanning. In the process of theMicro-LIBS analysis, the object is moved step by step in micro-level, every scanpoint is required to be focused. For the needs of Micro-LIBS technology, this paperdesigns and accomplishes a three-dimensional precision scanning system, in order torealize the Micro-LIBS microscopic focus and scanning during the process of thetechnical analysis.Micro-LIBS three-dimensional precision scanning system is called for the followingtasks:1) According to the needs of the Micro-LIBS system, a entire design plan isformulated, which including building the motor-driven platform, microprocessorselection and its program, PC serial communication and camera focusingfunction. 2) The control circuit board is for STM32microcontroller, which includes functionof the RS232communication and its protocol, the generation of PWM waveform,acquisition of the limit sensor etc.3) The control software is programmed by LabVIEW, which mainly completes theserial communication and focusing evaluation of camera.Finally, Micro-LIBS three-dimensional precision scanning system is tested integrally,the result shows that the motor-driven platform’s single step is0.1m, it candetermine the focusing position of the camera significantly with the LabVIEWsoftware. The system can trace out the outline of undulating surface through matrixscan ideally.